1. Field of the Invention
The present invention relates to a drum-type washing machine, and more particularly, to a drum-type washing machine with a tub having an improved structure.
2. Description of the Related Art
In general, laundering using a drum-type washing machine is carried out using a frictional force between wash water and laundry that receives the driving force of a motor to perform washing. Such a method causes little damage to the laundry, prevents the laundry from getting tangled, and achieves such washing effects as beating and rubbing.
FIG. 1 illustrates a perspective view of an exterior of a general drum-type washing machine, and FIG. 2 illustrates a cross-sectional view of a drum-type washing machine in accordance with a related art.
As illustrated in FIG. 1, an opening la opened or closed by a door 8 is provided on a front surface of an outer case 1, and a drum 3 is rotatably provided therein for receiving laundry. On a surface of the drum 3, a plurality of holes through which the wash water passes is provided.
As illustrated in FIG. 2, on an outside of the drum 3, a tub 2 is provided for storing the wash water, and the tub 2 is coupled with a damper 10 and a spring 12 so as to be fixed to an outer case 1. On a central part of the door 8, a door glass 8a depressed inward of the drum-type washing machine is provided, and a gasket 7 is provided between the door 8 and the tub 2 for preventing the wash water from leaking. On a rear side of the tub 2, a motor 6 is provided for rotating the drum 3, and washing is performed by rotation of the drum.
FIG. 3 illustrates a cross-sectional view of a structure of a bearing housing on a rear side of the tub in accordance with the related art, and FIG. 4 illustrates a perspective view showing a rear side of the tub, and FIG. 5 illustrates a cross-sectional view of a rear side of the tub.
As illustrated in FIG. 3, a bearing housing 4 is provided on the rear side of the tub 2. On the central part of the bearing housing 4, a hole through which a rotating axis 6c of a motor 6 is provided, and a bearing securing smooth rotation of the rotating axis is provided.
Meanwhile, the motor 6 includes a rotor 6a and a stator 6b, and the stator 6b is fixed to the bearing housing 4. When power is supplied to the motor 6, the rotating axis 6c is rotated together with the rotor 6a. Therefore, the drum 5 coupled to an end of the rotating axis 6c is rotated and the washing is performed in the drum-type washing machine.
As illustrated in FIG. 4, the bearing housing 4 includes a hub 4a and a plurality of bridges 4b. The plurality of bridges 4b is extended in three directions at intervals of 120 degrees along a circumference of the hub 4a. In this case, on an upper part thereof, a carrying bolt 5 is coupled with an end of the bridge 4b. The carrying bolt 5 fixes the tub 2 to the outer case 1. Accordingly, the tub 2 is prevented from hitting against the outer case 1 during transportation of the drum-type washing machine.
For preventing weight of the outer case 1 is centered on a side thereof through the carrying bolt 5, a supplementary member 8 is inserted between the carrying bolt 5 and the outer case 1.
Referring to FIG. 3, a fixing bracket 9 is provided at each end of the plurality of bridges 4b. A first end of the bracket 9 is fixed to a side of the tub 2, and a second end of the bracket 9 is coupled with an end of the bridges 4b. 
In this case, a coupling hole to which a bolt 11 is coupled is provided at an end of the bridge 4b. Therefore, the bridge 4b is fixed to the bracket 9 by passing the bolt 11 through the bracket 9 and coupling to the coupling hole.
FIG. 5 illustrates a perspective view of a tub in accordance with a related art, and FIG. 6 illustrates a diagram showing a front side of an assembled structure of the tub.
As illustrated in FIG. 5, the tub 2 includes a center tub 21, a front tub 22, and a back tub 23. In this case, the center tub 21 is formed in a cylindrical form, and the back tub 23 covers a rear side of the center tub 21. A drum 3 is provided on an inner side of the tub 2, and n opening 2a is projected frontward from the front tub 22.
On a circumference of the front tub, a bending part bent in a “U” form is provided, and a sealing member is inserted to an inside of the bending part. A curled end of the center tub is inserted into the bending part.
A plurality of fixing apparatus formed in a buckle form is provided along an outer circumferential surface of the center tub. The fixing apparatus includes a hanger, and a lever. When the hanger is hanged on a circumference of the front tub and the lever is pulled, the front tub is pulled toward the cent tub and fixed thereto. In this instance, the sealing member is compressed to seal the front tub and the center tub.
Meanwhile, the abovementioned tub for the drum-type washing machine in accordance with the related art has problems as follows.
First, the tub and the bearing housing needs to be thick for preventing the tub and the bearing housing from being damaged because the bearing housing is fixed to the tub by the three bridges and vibration and weight generated during a high speed rotation are centered on the tub and the bearing housing.
Second, for preventing the weight is centered on a side of the outer case through the carrying bolt, a separated supplementary member needs to be provided.
Third, for coupling the bridges of the bearing housing with the tub, separate brackets are needed. Since the first end of the bracket is welded on a side of the tub, and the second end thereof is coupled with the bridge, assembling is not easy.
Fourth, a coupling force of the fixing apparatus for coupling the front tub with the center tub is uneven along a circumferential direction.
Fifth, it is difficult to assemble the fixing apparatus on the outer circumference of the center tub, thereby decreasing productivity of the tub.